Arylpyrrole compounds useful as insecticides, nematicides and acaricides and the preparation thereof from acrylonitrile and substituted N-(trimethylsilyl)-methyl-5-methylbenzenethioimidate compounds are described in copending patent application Ser. No. 392,495 filed on Aug. 11, 1989 now abandoned.
V. S. Karavan et al., Journal of Organic Chemistry (USSR), 5, pages 2161-2164 (1969) describe the preparation of 2-amino-3-cyano-5-arylfurans from the base catalysis of (substituted phenacyl)malononitrile compounds. However, no ring-closure to a pyrrole is reported therein.
A. O. Abdelhamid et al., Journal Fur Praktische Chemi, 331, pages 31-36 (1989) report the synthesis of substituted phenacylacetonitrile compounds using concentrated hydrochloric acid in acetic acid. However, only 2-amino-3-cyano-5-arylfurans are prepared from the substituted phenacylacetonitrile compounds.
It is therefore an object of the present invention to provide a new and efficient process for preparing 2-halo-3-substituted-5-arylpyrrole compounds.